/Engine/Source/Runtime/AIModule/Classes/BehaviorTree/BTCompositeNode.h
Get next child to process and store it in CurrentChild
int32 GetNextChild ( [FBehaviorTreeSearchData](API\Runtime\AIModule\BehaviorTree\FBehaviorTreeSearchData) & SearchData, int32 LastChildIdx, [EBTNodeResult::Type](API\Runtime\AIModule\BehaviorTree\EBTNodeResult__Type) LastResult ) const